a) Field of the Invention
This invention relates to a new or improved variable ratio drive pulley. Such drive pulleys are widely used in belt drive transmissions for vehicles such as snowmobiles to provide both a clutch and a speed responsive variable drive ratio.
b) Description of the Prior Art
As used in snowmobiles, such drive pulleys are attached to the output shaft of the engine and comprise a fixed flange and a movable flange between which is engaged a transmission drive belt, the pulley containing weighted levers or the like which are influenced by the rotational speed of the pulley to displace the movable flange towards the fixed flange as the speed of rotation increases so that the radius at which the transmission belt is engaged between the flanges increases. Examples of such variable diameter drive pulleys can be seen in our Canadian Patents 985,931 and 1,208,040.